Obsolete French Threads

So I've answered this to my self may of times, which is no, but its worth a try:

Is there an alternative bottom bracket for my old skoo Peugeot besides the Phil Wood BB cups. I was thinking of re tapping the threads to maybe an Italian threading, you know something more accessable will that work or will I destroy a frame?

I've heard of force fitting a British threaded cartridge bottom bracket, but I'm not going to try it on my PX10! Actually, it probably won't hurt the shell because it's steel and the BB is aluminum. It's just not the right way to do things.

I think I'm going to try an Edco from Velo Orange since I want to use a NR triple on my Peugeot. The 120mm spindle should be about right and the Edco makes the chainline adjustable to some extent.

I'm not convinced that a cartridge bottom bracket is a big improvement and I'm afraid that there won't be replacements for square taper cartridge bottom brackets available a few years down the road. I'm only willing to try the Edco because I can't find the spindle I need. I've got a couple of new NR thickwall cupsets, but Campy never made a spindle for a Record triple and thickwall cups.

I'll leave my machete at home, JK. No thanks I have spares, is there any way to alter the BB shell so I can install a sealed cartridge BB.

Since we're just hashing things up: I'd bet you could install 2 BSC (both RH thread) *adjustable* side cups in your FR BB with only minor swearing and no machine shop visit required. You WOULD need one of the Shimano units with both removable cups and 2 of the *alloy* cups would be best (avoid the plastic cups) since you would be doing some forced minor deformation of the threads. This would allow you to select whatever size spindles Shimano made of those UN-73s(?), and then you can fit a modern-ish JIS crank as well...otherwise it's a lot of fussing and cobbling if you have good FR cups and a crank/spindle that fits, already.

In the latest issue of Bicycle Quarterly, Jan Heine describes how to install sealed bearings in a British- or French-threaded b/b. Takes some bit of machining, but you get larger bearings and ready renewability.

That works only with a Swiss-threaded bottom bracket, unless you can cross-thread a LH 24TPI cup into a RH 1mm BB shell. (The dual RH thread cup approach outlined above should work, as well.) If you use aluminum cups, there is virtually no danger of damaging your steel BB shell. For almost 10 years my PKN-10 has had an English-threaded Sugino fixed cup and a French-threaded adjustable cup.

So I've answered this to my self may of times, which is no, but its worth a try:

Is there an alternative bottom bracket for my old skoo Peugeot besides the Phil Wood BB cups. I was thinking of re tapping the threads to maybe an Italian threading, you know something more accessable will that work or will I destroy a frame?

Cheers,
Michelle

Yes, you CAN re thread the BB. We've done this (re-tapped for an Italian BB) and it will works out nicely - so long as the BB shell is thick enough so you are not shaving the shell down to the thickness of a tin can. With better quality bikes the shells always seem to be thicker. With some of the low-end bikes they may have used thinner welded sheet steel to form the BB, so look for a seam or weld line.

The real advantage to doing so would be to use a more modern style of crankset. Otherwise, If you plan to keep a square tapered crankset, and if the cups are still in decent condition, I wouldn't bother. You can still find replacement spindles in N.O.S. condition for a reasonable price on eBay, and with a change of ball bearings (higher grade preferred) the bike should run just fine for a very long time.

Curious... what were your ultimate intentions for making the BB change?

One additional thing on my retapped BB (from your mech forum thread). When I went from the cup/cone that was in the retapped shell to a sealed unit I had to do some additional grinding in the shell, in the area between the threaded ends, to get the sealed unit (a Campy Chorus) to drop in correctly.

Those YST bottom brackets require chamfering of the bottom bracket shell like the old Mavic units. You have to find a shop that has the tool and someone that knows how to use it. It won't be cheap and you'll end up with a POS bottom bracket. Phil Wood probably won't cost much more and you'll have a lifetime bottom bracket.